EP2284141A1 - Method and device for the manufacture of coal particles enriched with minerals - Google Patents

Abstract

Producing carbon particles (2) enriched with minerals (4) from a biogas plant, is claimed. An independent claim is included for a device for executing the above process, comprising a cylindrical container (1), which is separated into two superimposed disposed part containers by a sieve, where the part container below the sieve is useful for receiving the liquid phase and exhibits at least a feed line for liquids, and the part of the containers above the sieve is useful for receiving the carbon particles and exhibits at least a supply for the carbon particles and at least one feed line for liquids.

Description

The present invention relates to a method and apparatus for producing mineral-enriched carbon particles and to the use of the mineral-enriched coal.

By introducing coal particles into agricultural soils, a variety of positive effects can be achieved. Due to the adsorption effect of the carbon particles increases the ability of the soil for plant nutrients and water ( Glaser B., Haumaier L., Guggenberger G., Zech W. 2001. The Terra Preta phenomenon: a model for sustainable agriculture in the humid tropics. Natural Sciences, 88, 37-41 ). This allows a better supply of the crop and thus higher crop yields. At the same time, due to the adsorption effect, it is expected that the aquifer will be relieved, inter alia, of fertilizers, pesticides and heavy metals. If, instead of fossil coal, a coal (biochar) technically produced from biogenic sources is used, the previously biologically fixed CO _{2 can be} permanently removed from the atmosphere. It creates a sustainable C-sink.

With regard to the production of biochar, it is basically possible to distinguish between two processes: hydrothermal carbonization (HTC) and pyrolysis.

For performing an HTC, various methods are known in the art. The WO 2008/138637 describes a method and apparatus for hydrothermal carbonization (HTC) of biomass with an HTC plant. In the WO 2008/113309 becomes a procedure for the wet-chemical conversion of biomass by hydrothermal carbonization. EP-A-1 970 431 describes an apparatus and a method for hydrothermal carbonization of biomass. WO-A-2008/095589 describes the hydrothermal carbonization of biomass, DE-A-102007062811 discloses produced from biomass materials and / or fuels and in the DE-U-202008012419 a device for the treatment of biomass is claimed.

Pyrolysis processes are also known in the art. So will in the DE-A-102005030096 an energy conversion system for solid biomass described. The DE-A-3531605 discloses a reactor for treating organic matter and methods for obtaining a plurality of intermediate and final products from these compositions. Method and device for storing and recovering bioenergy is used in the DE-A-3048320 discloses and finally describes the DE-A-3048320 a method and apparatus for the combined production of high quality pyrolysis oils, biochar and generator gas from organic feedstocks.

Both fossil coal and biochar in the untreated state are only very suitable for use in soil. In essence, this can be attributed to the high sorption capacity of the coal, by which the plant nutrients present in the soil can be fixed so far that the plant growth is disturbed.

With respect to the preparation of a coal-based soil conditioner, various methods are known.

Out WO-A-2000/037394 For example, a process is known in which an organic fertilizer of humic character is produced from brown coal by oxidizing and ammonifying treatment. In the WO-A-2009/021528 describes a fermentative process for the production of humus- and nutrient-rich and water-storing clay soil substrates using pyrogenic carbon.

Both references describe methods for converting coal and other carbonaceous feedstocks to humus or a humus-like material. These processes are associated with a considerably higher cost than the sole achievement of a saturation of sorption. So are in accordance with the WO-A-2000/037394 high temperatures and pressures required. For the method according to the WO-A-2009/021528 long periods of two to six weeks are planned.

The object of the invention is to provide an economically efficient method by means of which coal particles are produced which have complete or at least substantial saturation of the sorption capacity and which are loaded with fertilizer-active minerals.

The object is achieved by a method according to claim 1. Advantageous embodiments of the method according to the invention are characterized in the dependent claims.

Another object of the present invention is an apparatus for performing the method according to claim 11.

Another object of the present invention is a mineral loaded coal for use as Soil improvers or for the incorporation of coal particles into agricultural soils for fertilization purposes.

The object is achieved by a method for the production of enriched with minerals coal particles, loading coal particles with minerals from a biogas plant.

• Einbringen der Kohlepartikel in einen Reaktionsbehälter;
• in Kontakt bringen der Kohlepartikel mit den Mineralstoffen unter Beladen der Kohlepartikel mit den Mineralstoffen, wobei die Mineralstoffe aus einer Biogasanlage entnommen und in einem fluidischen Träger enthalten sind;
• Austragen der beladenen Kohlepartikel aus dem Reaktionsbehälter; und
• Entwässerung der beladenen Kohlepartikel unter Erhalt von beladenen und entwässerten Kohlepartikeln.

The procedure is performed by performing the following steps:

• Introducing the carbon particles into a reaction vessel;
• contacting the carbon particles with the minerals while loading the coal particles with the minerals, the minerals being taken from a biogas plant and contained in a fluidic carrier;
• Discharging the loaded coal particles from the reaction vessel; and
• Dewatering of the loaded coal particles to obtain laden and dehydrated carbon particles.

Preference is given to a method in which one loads the coal particles with minerals, wherein the minerals
via a circulating in the biogas plant, largely solids-free liquid phase or
via a liquid phase separated from the solids-containing fermentation medium of the biogas plant or via a gas phase generated from the fermentation medium of the biogas plant or
via the biogas formed in the biogas plant or via a combination of said steps from the biogas plant removes.

Also preferred is a process in which carbon particles are used from a coal which is obtained by a thermochemical process from organic materials.

Particularly preferred is a process in which the coal is produced essentially from the organic residues of the biogas plant.

Preference is also given to a process in which the coal particles are comminuted or pressed into briquettes before being introduced into the reaction vessel.

Very particular preference is given to a process in which the energy required for pretreatment, loading and / or aftertreatment of the coal is generated by means of the biogas plant.

Preference is also given to a process in which mineral-containing gaseous and / or liquid by-products of the coal production are fed to the reaction vessel and / or the biogas plant.

Also preferred is a method in which one exchanges the liquid phase between the biogas plant and the reaction vessel.

Also particularly preferred is a process in which the charged carbon particles are dried in the reaction vessel by supplying a gas which contains oxygen and / or which is heated before being fed.

The present invention also provides an apparatus for carrying out the method according to the invention, comprising a substantially cylindrical vessel which is divided by a sieve into two sub-vessels arranged one above the other, the sub-vessel below the sieve for receiving the liquid phase is and has at least one supply for fluids and the sub-vessel above the screen for receiving the carbon particles is provided and having at least one feed for the carbon particles and at least one feed for fluids.

According to the invention, a device is preferred which has a screw conveyor for the discharge of the carbon particles or that has a stirring device for mixing the suspension of the carbon particles.

Particularly preferred is a device which has gas-tight locks for the input and output of the coal.

A further subject of the present invention is coal loaded with minerals, obtainable by a process according to the invention, for use as a soil conditioner or for the introduction of coal particles into agricultural soils for fertilization purposes.

The object is thus achieved in that the coal particles are brought into contact with selectively decoupled from a biogas plant fertilizing minerals.

A solution according to the invention includes making available the necessary minerals both from the fermentation liquid of the biogas plant and from the biogas formed in the biogas plant, whereby both substances are cleaned at the same time. Another preferred solution provides for the production of coal from the organic fermentation residues of the coupled biogas plant. Particularly advantageously, the method can be designed if the biogas plant allows a two-phase mode of operation. The design of the invention Device, namely the reaction vessel for carrying out the loading of the coal, may for example have a coal suspension or a coal fixed bed.

Fluids in the sense of the invention are gaseous or liquid media. These can be, for example, biogas, exhaust gases from biogas plants, reaction solutions from biogas plants, wastewaters and the like.

Brief description of the figures

• FIG. 1 Figure 3 illustrates in flow chart form an example of a process for the production of mineral enriched coal particles with starting coal of indeterminate origin;
• FIG. 2 shows in the form of a flow chart an example of a method for the production of mineral-enriched coal particles with the use of biogenic coal (biochar), which is produced from the organic residues of the biogas plant;
• FIG. 3 Fig. 3 illustrates in flow chart form an example of a process for producing mineral-enriched coal particles in conjunction with a bi-phase biogas plant;
• FIG. 4 shows the design of the reaction vessel for loading the coal with minerals in a variant with a coal suspension; and
• FIG. 5 shows the design of the reaction vessel for loading the coal with minerals in a variant with a coal fixed bed.

Detailed description of the invention

With reference to the following description and with reference to the accompanying figures, the invention will be described in more detail. It is clear that the preferred embodiments indicated below do not limit the scope of the present invention, but allow the person skilled in the art further variants of the method, which likewise belong to the subject matter of the present invention.

Various variants in the form of exemplary embodiments are described for carrying out the method according to the invention.

FIG. 1 shows an embodiment of the invention for a single-phase biogas plant and coal particles of indeterminate origin. The loading of the coal particles 2 with minerals 4 from a biogas plant 7 takes place in the reaction vessel 1.

To optimize the sorption properties of the carbon and the mechanical stability, a pre-treatment can be helpful. These include, but are not limited to, crushing, briquetting, treatment with chemicals for activation, doping or impregnation of coal, and drainage. Preferably, the carbon particles or the coal briquettes have a diameter or a layer thickness which is less than 20 mm on average.

So that the minerals can be optimally brought into contact with the coal, the solid particulate components must first be separated from the fermentation liquid 6 of the biogas plant.

This is done by the phase separator 5. The phase separator 5 separates the fermentation liquid 6 in one solid phase and a mineral-containing, liquid or gaseous phase, wherein only the liquid and gaseous phase are fed to the reaction vessel 1.

The recovery of the liquid phase can take place either via sieves or filters as well as via a spontaneous or forced sedimentation in non-mixed containers or centrifuges. The concentration of the liquid phase on the elements N, P, K is preferably more than 100 mg / kg in total, while the concentration of filterable solids is preferably below 1000 mg / kg.

For the deposition of a mineral-containing gas phase, the phase separator 5 has a gas-tight container. To accelerate the transition to the gas phase, the use of suitable measures in the container is recommended. These include, for example, increasing the temperature, lowering the pressure, the use of pH-changing chemicals and the passage of a gas phase (also known as stripping). The gas phase may be air or biogas or recirculated gas from the reaction vessel 1. While it is recommended for the separation of gaseous ammonia nitrogen, an increase in the pH in the basic range, preferably above pH 9, the separation of gaseous sulfur in the Binding H ₂ S most effectively in an acidic medium under pH 6 done.

In addition to the minerals that have been deliberately separated from the fermentation liquid, additional minerals from the biogas produced in the biogas plant can be used to load the biochar. This can be done by introducing the biogas into the bottom region of the reaction vessel 1 in a simple manner. By this design at the same time usually necessary for biogas biogas purification is performed, so that the expense of additional cleaning can be omitted. With this configuration, care must be taken to ensure that 1 is a gas-tight container and that in the case of the possible supply of a specifically generated, mineral-containing gas phase from 5, the biogas 8 is not so far mixed with foreign gas constituents that the purified, gaseous energy source 10 represents an ignitable mixture. In particular, attention should be paid to the oxygen content, which should be less than 2 vol .-% in the gas 10.

A preferred embodiment of the method provides for drainage of the laden with minerals coal particles. This reduces the transport effort and allows the simultaneous production of processed excess water 11, for which there are different recovery options inside and outside the process chain. Thus, the excess water 11 can be used for example as a reaction and transport medium in the biogas plant 7 or used for irrigation of agricultural crops. The drainage is preferably carried out in two or more steps. Preferably, the reaction vessel 1 is used for partial drainage. By built-in sieves and / or sedimentation of the solids, the liquid phase can be removed separately. The pre-dewatered, loaded coal particles 3 are preferably dehydrated in further steps to a coal 9 with a water content of less than 30 mass%. This can be done in a separate drainage system 12 with mechanical and thermal dewatering units. For mechanical dewatering centrifuges and screw or chamber filter presses are suitable. The thermal dehydration is ideally operated with the waste heat 14 from a plant 13 for the energetic use of the gaseous energy carrier 10. Alternatively, the entire drainage including a thermal water separation also in container 1. In contrast to the first variant, no continuous process in container 1 can be established by the thermal dehydration in the alternative variant. Nevertheless, in order to be able to continuously purify the biogas produced, it is recommended to use at least two reaction vessels 1 to be operated in parallel. Instead of a technical drainage, the drainage can also be effected by solar influence in the form of a simple bed with or without roofing.

In FIG. 2 an alternative embodiment of the method according to the invention is shown. This embodiment relates to the use of organic fermentation residues as the starting material of the coal, these fermentation residues from the same biogas plant as the minerals for the loading of the coal. This coal is also referred to below as biochar.

The use of organic residues from a biogas plant as a source of coal has several advantages.

• Positive Umweltbilanz: Da Biokohle aus zeitnah von Pflanzen gebundenem CO₂ gewonnen wird, kann das Gesamtverfahren eine negative CO₂-Bilanz erreichen. Dies ermöglicht eine dauerhafte Entfernung von atmosphärischem CO₂.
• Gute Verfügbarkeit: Der organische Reststoff fällt zentral an der Biogasanlage an, aus der auch die zur Kohlebeladung notwendigen Mineralien stammen.
• Höhere Wirtschaftlichkeit der Biomassenutzung: Die zusätzliche Verwertung der in der Biogasanlage nicht abgebauten organischen Substanz kann die Wirtschaftlichkeit einer rein energetischen Nutzung der zur Biogaserzeugung verwendeten Biomassen erhöhen.
• Nutzung von Synergieeffekten bei der Kohleerzeugung: Die Kohleerzeugung 16 kann verbunden sein mit dem Anfall einer Gas- und/oder Flüssigphase. Diese Phasen können im Reaktionsbehälter 1 gereinigt werden. Anfallende Überschusswärme aus der Kohleerzeugung kann zur Trocknung der beladenen Kohle verwendet werden.

These include:

• Positive environmental performance: Since biochar is obtained from timely plant-bound CO ₂ , the overall process can reach a negative CO ₂ balance. This allows a permanent removal of atmospheric CO ₂ .
• Good availability: The organic waste material accumulates centrally at the biogas plant, from which the minerals required for coal loading also originate.
• Higher profitability of biomass utilization: The additional utilization of the organic substance not degraded in the biogas plant can increase the economic efficiency a purely energetic use of biomass used for biogas production.
• Use of synergies in coal production: Coal production 16 may be associated with the onset of a gas and / or liquid phase. These phases can be cleaned in the reaction vessel 1. Any excess heat from the coal production can be used to dry the loaded coal.

A particularly preferred design variant of this embodiment is in Fig. 2 shown. This contains a solid / liquid separation by a plant 5. The solid phase is fed to a plant for thermochemical carbonization 16, while the liquid phase with dissolved minerals, as in the example according to Fig. 1 , for loading the biochar 17 in the reaction vessel 1 is used. In addition to the biochar 17, a liquid phase 18 and / or a gas phase 19 can additionally arise depending on the design of the carbonization process in Appendix 16. Both phases can be advantageously cleaned in the reaction vessel 1. Subsequently, the two phases can be used as treated excess water 11 or gaseous energy source within or outside the process chain.

For the carbonization several methods are considered. These include pyrolysis and hydrothermal carbonation. Especially during pyrolysis, a previous dewatering of the solid phase 15 can be helpful. Preferably, the water content of 15 before carrying out the pyrolysis should have a mass fraction of less than 30%. In order to come to appropriate levels, the application of a thermal drainage is recommended. For this purpose, the system 12 can be used, in which the drying of the loaded biochar takes place. In front the addition of the biochar produced in container 1, it may be advantageous to the biochar according to the description in embodiment according to Fig. 1 prepare. In addition to the organic residues from a biogas plant, Annex 16 also contains other biogenic substances such as wood, straw and municipal waste.

The drainage of the loaded biochar can, as in embodiment according to Fig. 1 be described described.

In FIG. 3 is shown a further alternative embodiment of the method according to the invention. The embodiment according to the Fig. 3 refers to the use of organic fermentation residues as raw material of the coal, these fermentation residues from the same two-phase biogas plant as the minerals for the loading of the coal. The two-phase mode of operation of the biogas plant is characterized in that in addition to the biomass to be converted, a liquid phase is added in at least one of the biologically active containers of the biogas plant, which was previously separated from a high-solids fermentation medium. The separation of the fermentation medium to obtain the liquid phase can be carried out in the original container, another container or a machine for phase separation. The two-phase operation of the biogas plant causes a low-solids liquid phase to circulate in the system, which can be used as a transport medium for the transfer of different process-relevant substances.

• Die Biogasanlage produziert bereits einen festen organischen Reststoff. Dieser hat gegenüber dem flüssigen Fermentationsmedium einer einphasigen Biogasanlage eine höhere Energiedichte. Der energetische Aufwand für die Aufbereitung und Kohleerzeugung kann dadurch reduziert werden.
• Die Biogasanlage produziert bereits eine feststoffarme, mineralstoffreiche Flüssigphase. Im Vergleich zum feststoffreichen Fermentationsmedium einer einphasigen Biogasanlage reduziert sich der für den Einsatz zur Kohlebeladung notwendige Separationsaufwand deutlich oder entfällt ganz.
• Die zirkulierende Flüssigphase der Biogasanlage kann durch die Reinigungswirkung der Kohle kontinuierlich um solche gelöste Stoffe entlastet werden, die das Potenzial besitzen, den Prozess der Biogasbildung zu hemmen. Neben Stoffen wie Ammoniak und Schwefelwasserstoff gehören hierzu auch verschiedene organische Zwischen- oder Endprodukte des Biogasprozesses, wie langkettige Fettsäuren und Huminsäuren.
• Der Bedarf der im Biogasprozess aktiven Mikroorganismen hinsichtlich der Versorgung mit Spurenelementen kann durch entsprechende Mineralien aus der Biokohle vollständig oder teilweise gedeckt werden. Mit Hilfe der zirkulierenden Flüssigphase können die Mineralien gezielt rückgelöst und in die Biogasanlage rückgefördert werden. Der Zukauf an Spurenelementen entfällt oder wird reduziert.
• Lösliche organische Begleitstoffe der Kohleerzeugung können über die zirkulierende Flüssigphase in die Biogasanlage verlagert werden, wo sie von den Mikroorganismen abgebaut werden und dadurch die Biogasproduktion steigern. Dieses Vorgehen ist zusätzlich hilfreich, falls es sich bei den organischen Begleitstoffen um Schadstoffe wie Phenole oder PAKs handelt.

The use of a two-phase biogas plant to provide the necessary starting materials for the production The mineral-laden coal particles have several advantages over a single-phase biogas plant. These include:

• The biogas plant already produces a solid organic residue. This has a higher energy density compared to the liquid fermentation medium of a single-phase biogas plant. The energy expenditure for the treatment and coal production can be reduced thereby.
• The biogas plant already produces a low-solids, mineral-rich liquid phase. Compared to the solids-rich fermentation medium of a single-phase biogas plant, the separation effort required for use in coal loading is significantly reduced or completely eliminated.
• The circulating liquid phase of the biogas plant can be continuously relieved by the cleaning action of the coal to such dissolved substances, which have the potential to inhibit the process of biogas formation. In addition to substances such as ammonia and hydrogen sulfide, this also includes various organic intermediates or end products of the biogas process, such as long-chain fatty acids and humic acids.
• The needs of microorganisms active in the biogas process with regard to the supply of trace elements can be fully or partially covered by corresponding minerals from biochar. With the help of the circulating liquid phase, the minerals can be specifically redissolved and returned to the biogas plant. The purchase of trace elements is eliminated or reduced.
• Soluble organic by-products of coal production can be transferred to the biogas plant via the circulating liquid phase, where they are degraded by the microorganisms and thereby increase biogas production. This procedure is additional Helpful if the organic contaminants are pollutants such as phenols or PAHs.

A preferred embodiment of the method according to the invention is now in Fig. 3 shown. The preferred embodiment provides that the liquid phase 21 circulating in the two-phase biogas plant 20 is continuously exchanged with the liquid phase 22 from the reaction vessel 1 for loading the biochar. The solid phase 15 of the biogas plant 20 can be transferred directly into a coal production facility 16. Depending on the method of carbonization, however, the upstream connection of further drainage may be helpful. This is especially true for pyrolysis as a process for coal production. For the integration of the gas and liquid phase from the carbonization in the loading of the biochar and the further processing of the loaded biochar the same statements apply as in embodiments according to the Figures 2 or 1. The liquid phase 22 to be transferred from the reaction vessel 1 into the biogas plant 20 is identical in its chemical properties to the excess water 11 potentially dissipated from FIG. 1. Both substances can be obtained from 1 according to the embodiments according to FIGS Fig. 2 be separated. Due to the shift of the liquid phase into the biogas plant, excess quantities of liquid can also be removed elsewhere from the biogas plant.

The targeted control of the processes for coal production, loading and replacement of the circulating liquid makes it possible to treat the liquid phase in the reaction vessel 1 so that there are always optimal environmental conditions for the participating microorganisms in the biogas plant 20. Thus inhibitors of biogas formation can be deposited in 1 necessary trace elements from the biochar are redeemed and moved back into 20.

FIG. 4 shows an exemplary design of the reaction vessel 1 for loading the coal particles with minerals. In the container 1, a coal suspension 29 is generated. This variant is advantageous if primarily liquids and not gases are to be treated or greater variations in the properties of the coal and the supplied liquids are to be expected.

As in Fig. 4 represented, both the coal and liquids can be continuously supplied via the Einspülschacht 27. If the liquid phase to be supplied is sufficiently free of solids, it will, however, if it is not required for flushing in of the coal, preferably be supplied via sockets 25 to the bottom. As a result, the mixing of the container contents can be promoted at the same time, without additional energy.

A screen 30 separates the liquid phase 22 of the container contents. The liquid phase can be removed via nozzle 25. A concentrated or pre-dewatered mixture of loaded coal and liquid can be discharged via pipe 24. The gas phase is removed via nozzle 23. The mixing of the container contents is preferably assisted by a stirrer. However, it is also possible that the mixing with the aid of the gas introduced via nozzle 26 or the liquid supplied via nozzle 25 achieves a sufficient effect, in particular if parts of the two substances are returned from the reactor head back into the reactor bottom. When circulating the liquid phase, make sure that it is removed from the reactor head before removal is largely free of carbon particles. This can be done by installing another sieve in the head area or by using gravity sedimentation.

A thermal dehydration of the loaded coal is for example possible by a gas is passed from below via the nozzle 26 through the coal after the complete removal of the liquid phase 22 and discharged through pipe 23 again. It is possible that the required for the thermal dewatering of the gas by exothermic processes in the reaction vessel itself. An exothermic process is easily achieved by the supply of air. Thus it can be assumed that the gases and liquids originating from the biogas plant and transferred into the reaction vessel contain microorganisms which accumulate on the coal and are able to convert easily biodegradable constituents of the coal into heat and CO ₂ in the presence of oxygen , The reduction of coal around the readily biodegradable component does not affect the efficiency of the overall process, since these components are degraded relatively quickly in the soil. The sustainable function as a soil conditioner receives the coal due to their hardly degradable constituents.

Except in the periods of thermal dehydration, the reaction vessel 1 can be operated continuously. Due to the internal phase separation, it is possible to set the residence time of the liquid phase and the coal largely independently. Preferably, the coal remains in container 1 for a longer time than the liquid phase. Depending on the nature of coal and liquid, the other process conditions and the desired results is too expect the optimum residence time for the coal to be 6 to 72 hours and for the liquid phase 5 to 60 minutes. By circulating parts of the gas phase in the reaction vessel and the contact time of gas and suspension can be varied. However, a sufficiently intense contact should preferably be ensured by allowing the screen 30 or a separate nozzle system (not shown) to allow the gas to rise in a fine-peared manner.

The process of mineral loading can be accelerated by optimizing the process conditions. In addition to a homogeneous distribution of the substances involved in the process is to be expected that even higher temperatures accelerated adsorption is achieved. A heating of the container contents can be achieved by installing directly in this heating units, due to the convection preferably at the bottom, and / or by supplying a liquid or gas phase to be supplied outside the container 1 is heated and / or by still hot coal from a plant to thermochemical carbonation is introduced.

By deliberately influencing the process conditions, it is possible to obtain a selective loading of the biochar with certain minerals. In particular, the pH value has an influence on the selectivity of the process. The pH value can be influenced both by the targeted dimensioning of the metered addition of the different liquid and gas phases to be treated and by the addition of basic or acidic chemicals. In the event that as in the embodiment according to Fig. 3 a return of the liquid phase 22 is provided in the biogas plant, the influence of the pH on the bond strength of coal and minerals can also be used to target the For the biogas process, trace elements need to be removed from the coal and relocated to the biogas plant.

In principle it is possible to operate several reaction vessels in series or in parallel. By means of a cascade-shaped construction and / or a variation of the process conditions, the coal can thereby be loaded selectively with different minerals.

Control of the coal loading process may be based on various measures. These include, in particular, the pH value and the electrical conductivity of the liquid phase, which make it possible to draw conclusions about the concentration of minerals. But also the optical properties of the liquid phase can allow conclusions about the concentration of the various ingredients. In order to obtain information on the degree of loading of the coal, various electrochemical measurement methods can be used. The use of sensors to determine the optical properties of the particle surface can also be effective.

An alternative variant of the container design shows FIG. 5 , If the coal particles and the liquid phase to be treated allow the structure and the permanent and uniform flow through a coal fixed bed 31, a corresponding fixed-bed reaction vessel can be operated. In the in Fig. 5 In the embodiment shown, the liquid phase is not dammed up, so that the pores of the fixed bed are mainly gas-filled. Due to the more intensive contact, this variant is particularly suitable if the minerals for the coal loading are to be supplied essentially via gases. To avoid blockages of the fixed bed, must Care should be taken to ensure that there is a substantial freedom of solids for any liquid phase to be supplied.

The unloaded coals are fed from above via a gas-tight lock 34. The loaded biochar is discharged at the container bottom via a discharge screw 32 and a gas-tight lock 35. Liquids to be introduced are applied uniformly over the cross-section of the container via the nozzle 33 with integrated nozzle. The arranged below the screw 32 sieve 30 separates as in the reactor according to Fig. 4 the liquid phase. The liquid phase is then removed via nozzle 25. The mineral-containing gas is supplied via nozzle 26 and discharged again after the flow through the fixed bed via pipe 23. As in the embodiment according to Fig. 4 If necessary, a liquid supplied below the sieve can be used to remedy or prevent sieve blockage. A thermal dewatering of the loaded coal is for example possible by, according to Fig. 4 , Air is supplied. This will be in Fig. 5 passed through the coal from below via spigot 26 and discharged again via spigot 23.

Except in the periods of thermal dehydration, the reaction vessel 1 can be operated continuously. The construction in Fig. 5 allows an independent adjustment of the residence times of coal and gas by the design of addition and removal. The contact time of the liquid phase in the fixed bed can be extended by pumping. Depending on the nature of coal and gas phase, the other process conditions and the desired results, it is expected that the optimum residence time for the coal 6 and 72 h and the optimum contact time for the gas phase is 0.1 to 30 seconds.

The process of mineral loading can be accelerated by optimizing the process conditions. In addition to a uniform passage of the gas and liquid phase through the fixed bed is to be expected that even higher temperatures accelerated adsorption is achieved. A heating of the container contents can be achieved by installing heating units directly therein and / or by heating a liquid or gas phase to be supplied outside the container 1 and / or by introducing the still hot coal from a system for thermochemical carbonization.

Regarding the optimization and control of the process of the biochar loading, the same statements apply as in the embodiment according to FIG Fig. 4 ,

LIST OF REFERENCE NUMBERS

1

Reaction vessel for loading the coal particles

2

uncharged coal of indeterminate origin

3

loaded and pre-dewatered coal

4

Minerals in the liquid or gaseous medium

5

Plant for phase separation

6

fermentation medium

7

biogas plant

8th

unprocessed biogas

9

loaded and dehydrated coal

10

purified gaseous energy source

11

Excess water

12

Plant for dewatering the loaded coal

13

Plant for energetic biogas use

14

warmth

15

solid phase of the fermenter content

16

Plant for thermochemical carbonation

17

Coal of biogenic origin (biochar)

18

Liquid phase of carbonation

19

Gas phase of carbonation

20

two-phase biogas plant

21

circulating liquid phase from (20)

22

Liquid phase of the reaction vessel

23

Nozzle for gas removal

24

Nozzle for removing loaded coal

25

Nozzle for discharging the liquid phase of the reactor contents (22)

26

Connecting piece for gas supply

27

Einspülschacht for unloaded coal

28

stirrer

29

Carbon suspension

30

scree

31

Carbon fixed bed

32

Coal discharge screw

33

Supply of liquid with nozzle for horizontal homogenization of the application

34

Supply shaft for unloaded coal with gas-tight lock

35

Discharge shaft for loaded coal with gas-tight lock

Claims (15)

Process for the production of mineral-enriched coal particles, wherein coal particles (2) are loaded with minerals (4) from a biogas plant (7). Method according to claim 1, characterized in that the following steps are carried out: Introducing the carbon particles (2) into a reaction vessel (1); bringing the coal particles (2) into contact with the minerals (4) while loading the coal particles with the minerals (4), the minerals (4) being taken from a biogas plant (7) and contained in a fluidic carrier (4, 8) ; Discharging the loaded coal particles (3) from the reaction vessel (1); and Dewatering the loaded coal particles (3) to obtain loaded and dewatered carbon particles (9). Method according to claim 1 or 2, characterized in that the coal particles (2, 17) are loaded with minerals (4), whereby the minerals (4)
via a liquid phase (21, 22) which circulates in the biogas plant (7, 20) and is largely solids-free or via a liquid phase (4) or separated from the solids-containing fermentation medium (6) of the biogas plant (7, 20)
via a gas phase (4) or gas generated from the fermentation medium of the biogas plant (7)
via the biogas (8) or biogas plant (7, 20) formed in the biogas plant (7, 20)
via a combination of said steps from the biogas plant (7, 20) takes. Method according to one of the preceding claims, characterized in that coal particles (4) are used from a coal which is produced by a thermochemical process from organic materials. A method according to claim 4, characterized in that one produces the coal particles (4) substantially from the organic residues of the biogas plant (7). Process according to Claim 1 or 2, characterized in that the coal particles (4) are comminuted before introduction into the reaction vessel. A method according to claim 1 or 2, characterized in that the coal particles (4) are pressed into briquettes before being introduced into the reaction vessel. Method according to one of the preceding claims, characterized in that one generates the energy required for the pretreatment, loading and / or aftertreatment of the coal particles (4) by means of the biogas plant (7). Method according to one of the preceding claims, characterized in that one feeds mineral-containing gaseous and / or liquid by-products of coal production to the reaction vessel (1) and / or the biogas plant (7). Method according to one of the preceding claims, characterized in that one exchanges the liquid phase between the biogas plant (7) and the reaction vessel (1). A method according to claim 1 or 2, characterized in that drying the loaded coal particles (3) in the reaction vessel by supplying a gas which contains oxygen and / or which is heated prior to feeding. Device for carrying out the method according to one of the preceding claims, consisting of a substantially cylindrical vessel (1), which is divided by a sieve (30) into two sub-vessels arranged one above the other, wherein the sub-vessel below the sieve (30) for receiving the liquid phase (22) is provided and at least one feed (25, 26) for fluids and the sub-vessel above the screen (30) for receiving the carbon particles (2) is provided and at least one feed (27, 34) for the carbon particles (2) and at least one supply (23, 24, 33) for fluids. Apparatus according to claim 12, characterized in that it comprises a screw conveyor for the discharge of the carbon particles (2) or that this has a stirring device for the mixing of the suspension of the carbon particles (2). Apparatus according to claim 11, characterized in that it comprises gas-tight locks for the introduction and discharge of the carbon particles. Mineral laden coal obtainable by a process according to any one of claims 1 to 11 Use as a soil improver or for incorporation of coal particles into agricultural soils for fertilization purposes.

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